s_1

s_2

s_1 = Vector((3, 2, -6))
s_2 = Vector((-4, 1, 8))
P: (1, 0, 7)
u = Translate(s_1, P)
v = Translate(s_2, P)
f = Line(P, s_1)
g = Line(P, s_2)
α = Angle(g, f)